Audio Clicks issue in ALSA application

#include <stdio.h>
#include <stdlib.h>
#include <alsa/asoundlib.h>
#define BUF_BYTES 128
 
int main (int argc, char *argv[]) {
	int err, rc ;
	unsigned char buf_right[BUF_BYTES];
	unsigned char buf_left[BUF_BYTES];
	 //char *buf;
	int size; 
	snd_pcm_t *playback_handle_right;
	snd_pcm_t *capture_handle_right;
	
	snd_pcm_t *playback_handle_left;
	snd_pcm_t *capture_handle_left;


#if 0	
	char* device = "default";
	if (argc > 1) device = argv[1];
#endif
	char* crdevice ;
        char* prdevice ;
        char* cldevice ;
        char* pldevice ;


	unsigned int rate ;
	unsigned int nchannels = 1;
	snd_pcm_format_t format = SND_PCM_FORMAT_S16_LE;
	unsigned int buf_frames_right = BUF_BYTES / nchannels / 2;
	unsigned int buf_frames_left = BUF_BYTES / nchannels / 2;

        if(argc != 2 )
        {
            printf("\nUsage is : application  sampling_rate \n\n\t Ex: ./gsm_application_target 8000 \n\n\t Supported sampling rates are: \n\t 1) 8000 \n\t 2) 16000 \n\t 3) 32000 \n\t 4) 44100 \n\t 5) 48000 \n\n NOTE: Any number other than given sampling rate takes default as 48000\n\n");
            exit(1);
        }

        rate = (int)atoi(argv[1]);

        if(rate == 8000)
        {
           crdevice = "VINR8";
           prdevice = "VOUTR8";
           cldevice = "VINL8";
           pldevice = "VOUTL8";

           
        }else if(rate == 16000)
        {
            crdevice = "VINR16";
            prdevice = "VOUTR16";
            cldevice = "VINL16";
            pldevice = "VOUTL16";

        }else if(rate == 32000)
        {
            crdevice = "VINR32";
            prdevice = "VOUTR32";
            cldevice = "VINL32";
            pldevice = "VOUTL32";

        }else if(rate == 44100)
        {
            crdevice = "VINR44";
            prdevice = "VOUTR44";
            cldevice = "VINL44";
            pldevice = "VOUTL44";

        }else
        {
            crdevice = "VINR48";
            prdevice = "VOUTR48";
            cldevice = "VINL48";
            pldevice = "VOUTL48";
            rate = 48000;
        }



///// RIGHT CHANNEL 
newStart:
	if ((err = snd_pcm_open (&playback_handle_right, prdevice, SND_PCM_STREAM_PLAYBACK, 0)) < 0) {
	fprintf (stderr, "cannot open playback right audio device %s (%s)\n", prdevice, snd_strerror (err)); exit (1);
	}
	else
	{
	  printf("Opened Playback right audio device  successfully %s \n", prdevice);
	}
	
	if ((err = snd_pcm_set_params(playback_handle_right, format, SND_PCM_ACCESS_RW_INTERLEAVED, nchannels, rate, 1, 500000)) < 0) { /* 0.5sec */
	fprintf(stderr, "Playback right open error: %s\n", snd_strerror(err)); exit(1);
	}

	if ((err = snd_pcm_open (&capture_handle_right, crdevice, SND_PCM_STREAM_CAPTURE, 0)) < 0) {
	fprintf (stderr, "cannot open capture right audio device %s (%s)\n", crdevice, snd_strerror (err)); exit (1);
	}
	else
	{
	  printf("Opened Capture right audio device successfully %s \n", crdevice);
	}

	if ((err = snd_pcm_set_params(capture_handle_right, format, SND_PCM_ACCESS_RW_INTERLEAVED, nchannels, rate, 1, 500000)) < 0) { /* 0.5sec */
	fprintf(stderr, "capture right open error: %s\n", snd_strerror(err)); exit(1);
	}	

////LEFT CHANNEL
	if ((err = snd_pcm_open (&playback_handle_left, pldevice, SND_PCM_STREAM_PLAYBACK, 0)) < 0) {
	fprintf (stderr, "cannot open playback left audio device %s (%s)\n", pldevice, snd_strerror (err)); exit (1);
	}
	else
	{
	  printf("Opened Playback left audio device successfully %s \n", pldevice);
	}
	
	if ((err = snd_pcm_set_params(playback_handle_left, format, SND_PCM_ACCESS_RW_INTERLEAVED, nchannels, rate, 1, 500000)) < 0) { /* 0.5sec */
	fprintf(stderr, "Playback left open error: %s\n", snd_strerror(err)); exit(1);
	}

	if ((err = snd_pcm_open (&capture_handle_left, cldevice, SND_PCM_STREAM_CAPTURE, 0)) < 0) {
	fprintf (stderr, "cannot open capture left audio device %s (%s)\n", cldevice, snd_strerror (err)); exit (1);
	}
	else
	{
	  printf("Opened Capture left audio device successfully %s \n", crdevice);
	}

	if ((err = snd_pcm_set_params(capture_handle_left, format, SND_PCM_ACCESS_RW_INTERLEAVED, nchannels, rate, 1, 500000)) < 0) { /* 0.5sec */
	fprintf(stderr, "capture left open error: %s\n", snd_strerror(err)); exit(1);
	}



	while(1) {
///// RIGHT CHANNEL 
                /***** Read the Frames from the Capture Device ******/
                err = snd_pcm_readi(capture_handle_right, buf_right, buf_frames_right);
                if(err == -EPIPE)
                {
                    printf("capture right func: overrun!");
                    rc = snd_pcm_prepare(capture_handle_right);
                    if(rc < 0)
                    {
                       printf("Fail to recover from problem, Need to reopen the device\n");
                      // goto reStart;
                    }
                }else if(err < 0)
                {
                    fprintf (stderr, "read from audio interface right failed (%s)\n", snd_strerror (err));
                    rc = snd_pcm_recover(capture_handle_right,err,0);
                    if(rc < 0)
                    {
                       printf("Fail to recover from problem, Need to reopen the device\n");
                      // goto reStart;
                    }
                }else if(err != (int)buf_frames_right)
                {
                    fprintf(stderr, "short read, read %d frames\n", err);
                }


               /****  Write the capture frame to playback ******/
                err = snd_pcm_writei (playback_handle_right, buf_right, buf_frames_right);
                if(err == -EPIPE)
                {
                  printf("Playback right func: overrun!");
                  rc = snd_pcm_prepare(playback_handle_right);
                  if(rc < 0)
                  {
                      printf("Fail to recover from problem, Need to reopen the device\n");
                     // goto reStart;
                  }
                }else if(err < 0)
                {
                    fprintf (stderr, "write to audio interface right failed (%s)\n", snd_strerror (err));
                    rc = snd_pcm_recover(playback_handle_right, err, 0);
                    if(rc < 0)
                    {
                        printf("Fail to recover from problem, Need to reopen the device\n");
                        //goto reStart;
                    }
                }else if(err != (int)buf_frames_right)
                {
                    fprintf(stderr, "short write, write %d frames\n", err);
                }


////LEFT CHANNEL
	        /***** Read the Frames from the Capture Device ******/
                err = snd_pcm_readi(capture_handle_left, buf_left, buf_frames_left);
                if(err == -EPIPE)
                {
                    printf("capture right func: overrun!");
                    rc = snd_pcm_prepare(capture_handle_left);
                    if(rc < 0)
                    {
                       printf("Fail to recover from problem, Need to reopen the device\n");
                      // goto reStart;
                    }
                }else if(err < 0)
                {
                    fprintf (stderr, "read from audio interface right failed (%s)\n", snd_strerror (err));
                    rc = snd_pcm_recover(capture_handle_left,err,0);
                    if(rc < 0)
                    {
                       printf("Fail to recover from problem, Need to reopen the device\n");
                      // goto reStart;
                    }
                }else if(err != (int)buf_frames_left)
                {
                    fprintf(stderr, "short read, read %d frames\n", err);
                }
	        

		   /****  Write the capture frame to playback ******/
                err = snd_pcm_writei (playback_handle_left, buf_left, buf_frames_left);
                if(err == -EPIPE)
                {
                  printf("Playback right func: overrun!");
                  rc = snd_pcm_prepare(playback_handle_left);
                  if(rc < 0)
                  {
                      printf("Fail to recover from problem, Need to reopen the device\n");
                     // goto reStart;
                  }
                }else if(err < 0)
                {
                    fprintf (stderr, "write to audio interface right failed (%s)\n", snd_strerror (err));
                    rc = snd_pcm_recover(playback_handle_left, err, 0);
                    if(rc < 0)
                    {
                        printf("Fail to recover from problem, Need to reopen the device\n");
                       // goto reStart;
                    }
                }else if(err != (int)buf_frames_left)
                {
                    fprintf(stderr, "short write, write %d frames\n", err);
                }


	}
 
reStart:	fprintf (stderr, "close handles\n");
	        snd_pcm_close (playback_handle_right);
	        snd_pcm_close (capture_handle_right);

	        snd_pcm_close (playback_handle_left);
	        snd_pcm_close (capture_handle_left);
                sleep(2);              
                //goto newStart;
                
	        return 0;
}